The long term objectives of this project are to establish the recognition potential (RP) as a valid tool for studying perception and to use it to generate and test new ideas about the underlying processes. The proposed research will test three principles: The first is that the RP requires the conscious awareness of a recognizable image. Superimposed images will be presented. A subject will attend to one type, ignoring the other. A recognizable image that ordinarily evokes the RP should not do so if it goes unnoticed. The second principle is that RP latency reflects the speed of perception. This principle will be investigated in three paradigms in which speed of perception will be varied by priming, by using images that vary in the speed of identification, and by studying individual differences in subjects varying in their reading ability. The third principle is that RP amplitude depends on the magnitude of the attended visual area that is involved in processing of the recognizable images. This principle is suggested by source density analyses of the RP which have indicated that it is produced in a circumscribed patch of visual cortex. The principle will be investigated in two experiments in which the size of the area containing the recognizable images will be presented, and in which attention will be directed to small or large images imbedded within composite figures. It is anticipated that the results will provide additional valuable information regarding the character of the RP and will contribute to a fuller understanding of perception.